Impact of Immunopathy and Coagulopathy on Multi-Organ Failure and Mortality in a Lethal Porcine Model of Controlled and Uncontrolled Hemorrhage.

Uncontrolled hemorrhage is a major preventable cause of death in patients with trauma. However, the majority of large animal models of hemorrhage have utilized controlled hemorrhage rather than uncontrolled hemorrhage to investigate the impact of immunopathy and coagulopathy on multi-organ failure (MOF) and mortality. This study evaluates these alterations in a severe porcine controlled and uncontrolled hemorrhagic shock (HS) model. Anesthetized female swine underwent controlled hemorrhage and uncontrolled hemorrhage by partial splenic resection followed with or without lactated Ringer solution (LR) or Voluven® resuscitation. Swine were surveyed 6 h after completion of splenic hemorrhage or until death. Blood chemistry, physiologic variables, systemic and tissue levels of complement proteins and cytokines, coagulation parameters, organ function, and damage were recorded and assessed. HS resulted in systemic and local complement activation, cytokine release, hypocoagulopathy, metabolic acidosis, MOF, and no animal survival. Resuscitation with LR and Voluven® after HS improved hemodynamic parameters (MAP and SI), metabolic acidosis, hyperkalemia, and survival but resulted in increased complement activation and worse coagulopathy. Compared with the LR group, the animals with hemorrhagic shock treated with Voluven® had worse dilutional anemia, coagulopathy, renal and hepatic dysfunction, increased myocardial complement activation and renal damage, and decreased survival rate. Hemorrhagic shock triggers early immunopathy and coagulopathy and appears associated with MOF and death. This study indicates that immunopathy and coagulopathy are therapeutic targets that may be addressed with a high-impact adjunctive treatment to conventional resuscitation.

Prolyl hydroxylase domain inhibitor is an effective pre-hospital pharmaceutical intervention for trauma and hemorrhagic shock.

Pre-hospital potentially preventable trauma related deaths are mainly due to hypoperfusion-induced tissue hypoxia leading to irreversible organ dysfunction at or near the point of injury or during transportation prior to receiving definitive therapy. The prolyl hydroxylase domain (PHD) is an oxygen sensor that regulates tissue adaptation to hypoxia by stabilizing hypoxia inducible factor (HIF). The benefit of PHD inhibitors (PHDi) in the treatment of anemia and lactatemia arises from HIF stabilization, which stimulates endogenous production of erythropoietin and activates lactate recycling through gluconeogenesis. The results of this study provide insight into the therapeutic roles of MK-8617, a pan-inhibitor of PHD-1, 2, and 3, in the mitigation of lactatemia in anesthetized rats with polytrauma and hemorrhagic shock. Additionally, in an anesthetized rat model of lethal decompensated hemorrhagic shock, acute administration of MK-8617 significantly improves one-hour survival and maintains survival at least until 4 h following limited resuscitation with whole blood (20% EBV) at one hour after hemorrhage. This study suggests that pharmaceutical interventions to inhibit prolyl hydroxylase activity can be used as a potential pre-hospital countermeasure for trauma and hemorrhage at or near the point of injury.

In vitro evaluation of hyperosmotic canine plasma suitable for infusion.

OBJECTIVE: To determine the characteristics of canine freeze-dried plasma (cFDP) as it is serially diluted with sterile water. DESIGN: In vitro experimental study. SETTING: Government blood and coagulation research laboratory. ANIMALS: cFDP from a commercial manufacturer. INTERVENTIONS: Ten units of cFDP were reconstituted to 100%, 90%, 80%, 70%, 60%, 50%, and 40% of the recommended volume with sterile water. The resultant solutions were analyzed for coagulation factor activity (factors II, V, VII, VIII, IX, X, and XII as well as antithrombin), fibrinogen concentration, prothrombin time, activated partial thromboplastin time, viscosity, osmolality, and kaolin-activated thromboelastography. MEASUREMENTS AND MAIN RESULTS: Viscosity, osmolality, and turbidity properties of plasma were increased in a reconstitution volume-dependent manner, with the 40% suggested volume generating approximately 2-fold increases in each. Similarly, factor activity levels and fibrinogen concentration increased by approximately 2-fold over this range in a concentration-dependent manner. Prothrombin time declined from 11.4 seconds at 100% volume to 10.9 seconds at 70% before increasing to 11.9 seconds at 40%. Activated partial thromboplastin time increased exponentially from 21.8 seconds at 100% rehydration to 100.0 seconds at 40%. R-time on TEG increased from 3.1 to 13.9 minutes at 50% rehydration, while alpha angle declined from 61.3° to 24.7° over the same range, and the maximum amplitude initially increased from 13.2 mm at 100% water to 18.6 mm at 70% water before dropping back down to 14.6 mm at 50% water. No clotting was observed with 40% rehydration. CONCLUSIONS: The creation of hyperosmotic plasma from cFDP appears feasible with preservation of concentrated coagulation factors, although there are some unexplained effects that happen to coagulation functions at the highest concentrations tested using only 40%-50% of recommended rehydration volume. Further studies are needed to evaluate the hyperosmotic product in vivo.

Short-term assays for mesenchymal stromal cell immunosuppression of T-lymphocytes.

Introduction: Trauma patients are susceptible to coagulopathy and dysfunctional immune responses. Mesenchymal stromal cells (MSCs) are at the forefront of the cellular therapy revolution with profound immunomodulatory, regenerative, and therapeutic potential. Routine assays to assess immunomodulation activity examine MSC effects on proliferation of peripheral blood mononuclear cells (PBMCs) and take 3-7 days. Assays that could be done in a shorter period of time would be beneficial to allow more rapid comparison of different MSC donors. The studies presented here focused on assays for MSC suppression of mitogen-stimulated PBMC activation in time frames of 24 h or less. Methods: Three potential assays were examined-assays of apoptosis focusing on caspase activation, assays of phosphatidyl serine externalization (PS+) on PBMCs, and measurement of tumor necrosis factor alpha (TNFα) levels using rapid ELISA methods. All assays used the same initial experimental conditions: cryopreserved PBMCs from 8 to 10 pooled donors, co-culture with and without MSCs in 96-well plates, and PBMC stimulation with mitogen for 2-72 h. Results: Suppression of caspase activity in activated PBMCs by incubation with MSCs was not robust and was only significant at times after 24 h. Monitoring PS+ of live CD3+ or live CD4+/CD3+ mitogen-activated PBMCs was dose dependent, reproducible, robust, and evident at the earliest time point taken, 2 h, although no increase in the percentage of PS+ cells was seen with time. The ability of MSC in co-culture to suppress PBMC PS+ externalization compared favorably to two concomitant assays for MSC co-culture suppression of PBMC proliferation, at 72 h by ATP assay, or at 96 h by fluorescently labeled protein signal dilution. TNFα release by mitogen-activated PBMCs was dose dependent, reproducible, robust, and evident at the earliest time point taken, with accumulating signal over time. However, suppression levels with MSC co-culture was reliably seen only after 24 h. Discussion: Takeaways from these studies are as follows: (1) while early measures of PBMC activation is evident at 2-6 h, immunosuppression was only reliably detected at 24 h; (2) PS externalization at 24 h is a surrogate assay for MSC immunomodulation; and (3) rapid ELISA assay detection of TNFα release by PBMCs is a robust and sensitive assay for MSC immunomodulation at 24 h.

A novel, quantitative clot retraction assay to evaluate platelet function.

Blood platelets are crucial to prevent excessive bleeding following injury to blood vessels. Platelets are crucial for the formation of clots and for clot strength. Platelet activation involves aggregation, attachment to fibrin and clot retraction. Most assays that address platelet function measure platelet aggregation, not clot retraction. Here, we describe a 96-well-based clot retraction assay that requires a relatively short runtime and small sample volume. The assay involves continuous optical density monitoring of platelet-rich plasma that is activated with thrombin. The data can be analyzed using time-series analytical tools to generate quantitative information about different phases of clot formation and clot retraction. The assay demonstrated good repeatability and reproducibility and was robust to different calcium concentrations. Impairment of platelet bioenergetics, actin polymerization, fibrin interaction, and signaling significantly affected clot retraction and was detected and showed good agreement with light transmission aggregometry, suggesting that clot retraction is predictive of platelet function. Using this microplate clot retraction assay, we showed a significant difference in platelets stored in autologous plasma compared with platelet additive solution after 7 days of room temperature storage.

Platelets are cell fragments in the blood that are necessary for clot formation. They are crucial to preventing excessive bleeding following trauma. To form clots, platelets clump (aggregate) and attach to fibrin protein and cells inside the blood vessels to form strong web-like structures. Platelets also contract to pull the edges of the wound close. Most measurements of platelet function involve aggregation. This paper focuses on platelet contraction. Here, we describe a new assay to measure platelets contraction that is repeatable and reproducible. The assay uses standard and common laboratory equipment and can be performed by most laboratory personnel and has the potential to detect clinical pathologies of clot formation. The assay could be developed for bedside patient care where platelet function could be assessed rapidly and assist in the diagnosis of coagulation and platelet disorders.

Refrigerated human mesenchymal stromal cells as an alternative to cryostorage for use in clinical investigation.

BACKGROUND: Mesenchymal stromal cells (MSCs) and other therapeutic cells show efficacy for cardiac damage, neurological disease, chronic lung disease, pediatric graft versus host disease, and several inflammatory conditions. Based on their anti-inflammatory and immune-modulatory activities, responsiveness, and secretion of beneficial factors, cellular therapeutics may provide benefits in acute and chronic traumatic injury. However, the use of live cells presents logistical challenges, especially for military trauma. MSCs are generally shipped and stored frozen but require sterile handling before infusion. This requires skilled personnel and equipment not readily available in a forward medical treatment facility or even a small community hospital. METHODS: Commercial human bone marrow- and adipose-derived MSCs from multiple donors were cultured under standard conditions, harvested and stored at 4°C in solution for up to 21 days. Cell viability, ATP content, apoptosis, proliferation capability, immunomodulation activity, and responsiveness were assessed after different amounts of time. RESULTS: Human MSCs can be stored at 4°C in MSC culture medium for 14 days while maintaining a reasonable level of viability and function. Both viability and function are reduced when MSCs are stored in crystalloid solutions. CONCLUSIONS: This approach makes it feasible to prepare cellular therapeutic agents in a laboratory or commercial facility and ship them under refrigerated conditions. Once they reach their destination, they can be stored at 4°C under conditions similar to blood products. Cells prepared and stored this way could also be used directly with minimal handling, making them more practical for both civilian and military trauma.

Risk of Harm in Needle Decompression for Tension Pneumothorax.

INTRODUCTION: Tension pneumothorax (TPX) is the third most common cause of preventable death in trauma. Needle decompression at the fifth intercostal space at anterior axillary line (5th ICS AAL) is recommended by Tactical Combat Casualty Care (TCCC) with an 83-mm needle catheter unit (NCU). We sought to determine the risk of cardiac injury at this site. METHODS: Institutional data sets from two trauma centers were queried for 200 patients with CT chest. Inclusion criteria include body mass index of =30 and age 18-40 years. Measurements were taken at 2nd ICS mid clavicular line (MCL), 5th ICS AAL and distance from the skin to pericardium at 5th ICS AAL. Groups were compared using Mann-Whitney U and chi-squared tests. RESULTS: The median age was 27 years with median BMI of 23.8 kg/m2. The cohort was 69.5% male. Mean chest wall thickness at 2nd ICS MCL was 38-mm (interquartile range (IQR) 32-45). At 5th ICS AAL, the median chest wall thickness was 30-mm (IQR 21-40) and the distance from skin to pericardium was 66-mm (IQR 54-79). CONCLUSION: The distance from skin to pericardium for 75% of patients falls within the length of the recommended needle catheter unit (83-mm). The current TCCC recommendation to "hub" the 83mm needle catheter unit has potential risk of cardiac injury.

Metabolic effects of radiation on red blood cells from cold stored whole blood.

BACKGROUND: The risk of military and civilian radiation exposure is increasing, and determining the effects of exposure is a high priority. Irradiation of the nearby blood supply after a nuclear event may impede mobilization of blood products for resuscitation at a time of great need. RBCs are administered to patients with trauma and hemorrhage to transport and deliver oxygen and avoid tissue hypoxia. Here we determine the effects of ionizing radiation on the energy metabolome of RBCs isolated from cold stored whole blood to determine if their stability is compromised by radiation exposure. STUDY DESIGN AND METHODS: Whole blood from healthy volunteers was subjected to 0, 25, or 75 Gy of X-irradiation, and stored at 4°C. RBCs were isolated from stored WB at 0, 1, 7, 14, and 21 days of storage. The levels of extracted Krebs cycle intermediates, nicotinamide adenine dinucleotides, and phosphorylated derivatives of adenosine and guanosine were determined by tandem mass spectroscopy. RESULTS: Irradiation at either 25Gy or 75Gy had no significant effect on any parameter measured compared to control (0Gy). However, there was a significant change over time in storage for ATP, GDP, and guanosine. DISCUSSION: Irradiation at doses up to 75Gy had no effect on the energy metabolome of RBCs prepared from blood stored at 4°C for up to 21 days, suggesting that the RBC energy metabolome is not affected by radiation exposure and the blood can still be used for resuscitation in trauma patients.

Cold storage of whole blood in an additive solution containing apoptotic and necrotic inhibitors.

BACKGROUND: Whole blood (WB) reigns superior to component therapy for the treatment of hemorrhagic shock on the battlefield. Though cold storage of WB offers a shelf life of 21 to 35 days, storage lesions and the potential for blood wastage remain. Storing WB in an additive solution (AS) containing apoptotic inhibitors may help preserve blood cell viability and improve blood quality over extended cold storage. STUDY DESIGN AND METHODS: Non-leukoreduced WB was obtained from healthy individuals and dosed with: AS, AS+Necrostatin-1 (AS+N1), AS+Boc-D-fmk (AS+B; apoptosis inhibitor), AS+Q-VD-OPh (AS+Q; apoptosis inhibitor), and Control (0.9% saline). Blood bags were kept refrigerated (1°-6°C) for 21 days. Bags were tested on days 0, 7, 14, and 21 for complete blood count, metabolism, clot formation, aggregation function, platelet activation, and red blood cell quality. RESULTS: Platelet count was better preserved in all AS-containing samples. All groups displayed increased glucose consumption and lactate production with storage. Furthermore, all groups displayed a similar decline in clot strength (max amplitude) over the 21-day storage period. Bags that received AS displayed greater preservation of GPIIb expression and lower phosphatidylserine exposure. P-selectin expression was increased in all AS groups. DISCUSSION: Treatment of hemorrhagic shock with WB transfusion is logistically simpler than component therapy. Results from our study suggest that refrigerated WB stored with an AS containing apoptotic and necrotic inhibitors helps better preserve platelet count but does not improve platelet function. The future development of WB ASs is warranted to optimize both platelet quality and hemostatic function.

Comparison of platelet quality and function across apheresis collection platforms.

BACKGROUND: Platelet concentrates (PLT) can be manufactured using a combination of apheresis collection devices and suspension media (plasma or platelet additive solution (PAS)). It is unclear how platelet quality and hemostatic function differ across the current in-use manufacturing methods in the United States. The objective of this study was therefore to compare baseline function of PLT collected using different apheresis collection platforms and storage media. STUDY DESIGN AND METHODS: PLT were collected at two sites with identical protocols (N = 5 per site, N = 10 total per group) on the MCS® + 9000 (Haemonetics; "MCS"), the Trima Accel® 7 (Terumo; "Trima"), and the Amicus Cell Separator (Fresenius Kabi, "Amicus"). MCS PLT were collected into plasma while Trima and Amicus PLT were collected into plasma or PAS (Trima into Isoplate and Amicus into InterSol; yielding groups "TP", "TI" and "AP", "AI", respectively). PLT units were sampled 1 h after collection and assayed to compare cellular counts, biochemistry, and hemostatic function. RESULTS: Differences in biochemistry were most evident between plasma and PAS groups, as anticipated. MCS and TP had the highest clot strength as assessed by viscoelastometry. AI had the lowest thrombin generation capacity. Both TP and TI had the highest responses on platelet aggregometry. AI had the greatest number of microparticles. DISCUSSION: Platelet quality and function differ among collection platforms at baseline. MCS and Trima platelets overall appear to trend toward higher hemostatic function. Future investigations will assess how these differences change throughout storage, and if these in vitro measures are clinically relevant.

The impact of prehospital whole blood on hemorrhaging trauma patients: A multi-center retrospective study.

BACKGROUND: Whole blood (WB) use has become increasingly common in trauma centers across the United States for both in-hospital and prehospital resuscitation. We hypothesize that prehospital WB (pWB) use in trauma patients with suspected hemorrhage will result in improved hemodynamic status and reduced in-hospital blood product requirements. METHODS: The institutional trauma registries of two academic level I trauma centers were queried for all patients from 2015-2019 who underwent transfusion upon arrival to the trauma bay. Patients who were dead on arrival or had isolated head injuries were excluded. Demographics, injury and shock characteristics, transfusion requirements, including massive transfusion protocol (MTP) (>10 U in 24 hours) and rapid transfusion (CAT3+) and outcomes were compared between pWB and non-pWB patients. Significantly different demographic, injury characteristics and pWB were included in univariate followed by stepwise logistic regression analysis to determine the relationship with shock index (SI). Our primary objective was to determine the relationship between pWB and improved hemodynamics or reduction in blood product utilization. RESULTS: A total of 171 pWB and 1391 non-pWB patients met inclusion criteria. Prehospital WB patients had a lower median Injury Severity Score (17 vs. 21, p < 0.001) but higher prehospital SI showing greater physiologic disarray. Prehospital WB was associated with improvement in SI (-0.04 vs. 0.05, p = 0.002). Mortality and (LOS) were similar. Prehospital WB patients received fewer packed red blood cells, fresh frozen plasma, and platelets units across their LOS but total units and volumes were similar. Prehospital WB patients had fewer MTPs (22.6% vs. 32.4%, p = 0.01) despite a similar requirement of CAT3+ transfusion upon arrival. CONCLUSION: Prehospital WB administration is associated with a greater improvement in SI and a reduction in MTP. This study is limited by its lack of power to detect a mortality difference. Prospective randomized controlled trials will be required to determine the true impact of pWB on trauma patients. LEVEL OF EVIDENCE: Prognostic and Epidemiological; Level IV.

A prospective assessment of the time required to obtain one unit of fresh whole blood by civilian phlebotomists and Army laboratory technicians (68 K).

BACKGROUND: Resuscitation with blood products improves survival after major hemorrhage. Blood product administration at or near the point-of-injury (POI) amplifies this benefit. Size, weight, and cold-chain management challenges all limit the amount of blood medics can carry. Warm fresh whole blood (WFWB) transfusions from a pre-screened donor within the unit represent an alternative source of blood at the POI. We measured the time required for civilian and Army technicians performing phlebotomy frequently to obtain one unit of blood to serve as a goal metric for combat medics being trained in this skill. METHODS: We gathered demographic and experience data along with proportion of first intravenous cannulation attempt success, time to blood flow initiated, and time to unit draw complete. RESULTS: We prospectively enrolled 12 civilian phlebotomy technicians and 10 Army laboratory technicians performing whole blood collections on 50 and 68 donors respectively. The mean time from setup to needle insertion was 3.7 min for civilians versus 4.2 min for Army technicians. The mean time from blood flowing to the bag being full was 10.7 min versus 8.4 min for civilians versus Army technicians respectively. The mean bag weights were 514 g versus 522 g. First-pass intravenous cannulation success was 96% versus 98% respectively. CONCLUSIONS: We found a high first intravenous cannulation attempt success among both the civilian and Army technicians. Medians times were <5 min to obtain venipuncture and <11 min to obtain one unit. These findings provide time-based benchmarks for potential use during transfusion training among military medics.

A narrative review of prehospital hemorrhagic shock treatment with non-blood product medications.

BACKGROUND: Hemorrhagic shock remains a leading cause of death in both military and civilian trauma casualties. While standard of care involves blood product administration, maintaining normothermia, and restoring hemostatic function, alternative strategies to treat severe hemorrhage at or near the point of injury are needed. We reviewed adjunct solutions for managing severe hemorrhage in the prehospital environment. METHODS: We performed a literature review by searching PubMed with a combination of several keywords. Additional pertinent studies were identified by crossreferencing primary articles. Clinical experience of each author was also considered. RESULTS: We identified several promising antishock therapies that can be utilized in the prehospital setting: ethinyl estradiol sulfate (EES), polyethylene glycol 20,000 (PEG20K), C1 esterase inhibitors (e.g. Berinert, Cinryze), cyclosporin A, niacin, bortezomib, rosiglitazone, icatibant, diazoxide, and valproic acid (VPA). CONCLUSION: Several studies show promising adjunct treatment options in the management of severe prehospital hemorrhage. While some are rarely used, many others are readily available and commonly utilized for other indications. This suggests the potential for future use in resourcelimited settings. Human studies and case reports supporting their use are currently lacking.

Effects of radiation exposure and storage on the energy metabolome of platelets in whole blood.

BACKGROUND: Exposure to radiation through battlefield use of nuclear weapons, terrorist attacks or accidents at nuclear power plants is a current concern for the military. Beyond the risk of exposure to personnel is the intentional or accidental irradiation of our blood banking supply system. It is unknown how large doses of ionizing radiation affect storage of blood and blood products, including platelets. The major function of platelets is clot formation which includes aggregation, shape change, vesicle release, and fibrinogen attachment; these tasks require a significant amount of energy. Here, we determine whether the ionizing radiation effects the energy metabolome of platelets in storage. STUDY DESIGN AND METHODS: Fresh whole blood from healthy volunteers was subjected to 0, 25, or 75Gy of X-irradiation, and stored at 4°C. Platelets were isolated from stored WB at 0, 1, 7, 14, and 21 days of storage. Krebs cycle intermediates, nicotinamide adenine dinucleotides, and the tri-, di, and mono- phosphorylated versions of adenosine and guanosine were extracted and measured by tandem mass spectroscopy. RESULTS: Irradiation at either 25Gy or 75Gy had no significant effect on the amount of any metabolite measured compared to control (0Gy). However, there was a significant fall over time in storage for most of the metabolites measured. DISCUSSION: These data show that irradiation at high doses has no effect on the concentration of the energy metabolome of platelets derived from whole blood stored in 4°C for up to 21 days and suggests that platelets can maintain their metabolome even after radiation exposure.

Massive Transfusion Thresholds Associated with Combat Casualty Mortality during Operations in Afghanistan and Iraq: Implications for Role 1 Logistical Support Chains.

INTRODUCTION: Limited literature exists examining outcomes associated with alternative thresholds for massive transfusion outside of the historical definition of 10 units of packed red blood cells (PRBC) in 24 hours. This study reports the predictive accuracy of alternative thresholds for 24-hour mortality and explores implications for Role 1 care supply requirements. METHODS: We conducted a secondary analysis of data from the Department of Defense Trauma Registry (DODTR) spanning encounters from 1 January 2007 through 17 March 2020. We included all casualties who received at least 1 unit of either PRBC or whole blood. We calculated area under the receiver operator curve (AUROC) of blood product quantity received, including both PRBC and whole blood, as a predictor for mortality within 24 hours of arrival to a military treatment facility. We identified optimal predictive thresholds per Youden's index. RESULTS: We identified 28,950 encounters of which 2,608 (9.0%) entailed receipt of at least 1 unit of PRBC or whole blood. Most casualties sustained battle injuries (2,437, 93.4%) with explosives as the most common mechanism (1,900, 72.8%) followed by firearms (609, 23.3%). The AUROC for blood product received within 24 hours was 0.59. The optimal threshold for predicting 24-hour mortality per Youden's Index was 20 units (sensitivity of 34.9% and specificity of 78.6%). The threshold exceeding 90% sensitivity was 2 units; whereas, the threshold exceeding 90% specificity was 33 units. CONCLUSIONS: We identified a wide range of numbers of received blood products associated with short-term mortality based upon prioritization of sensitivity or specificity. This study found only 2 units of blood product received had a 90% sensitivity for predicting 24-hour mortality, highlighting the resource mobilization challenges that confront healthcare providers during resuscitation at the Role 1.

Clinical Assessment of Low Calcium In traUMa (CALCIUM).

Major trauma frequently occurs in the deployed, combat setting and is especially applicable in the recent conflicts with explosives dominating the combat wounded. In future near-peer conflicts, we will likely face even more profound weapons including mortars and artillery. As such, the number of severely wounded will likely increase. Hypocalcemia frequently occurs after blood transfusions, secondary to the preservatives in the blood products; however, recent data suggests major trauma in and of itself is a risk factor for hypocalcemia. Calcium is a major ion involved in heart contractility; thus, hypocalcemia can lead to poor contractility. Smaller studies have linked hypocalcemia to worse outcomes, but it remains unclear what causes hypocalcemia and if intervening could potentially save lives. The objective of this study is to determine the incidence of hypocalcemia on hospital arrival and the association with survival. We are seeking to address the following scientific questions, (1) Is hypocalcemia present following traumatic injury prior to transfusion during resuscitation? (2) Does hypocalcemia influence the amount of blood products transfused? (3) To what extent is hypocalcemia further exacerbated by transfusion? (4) What is the relationship between hypocalcemia following traumatic injury and mortality? We will conduct a multicenter, prospective, observational study. We will gather ionized calcium levels at 0, 3, 6, 12, 18, and 24 hours as part of scheduled calcium measurements. This will ensure we have accurate data to assess the early and late effects of hypocalcemia throughout the course of resuscitation and hemorrhage control. These data will be captured by a trained study team at every site. Our findings will inform clinical practice guidelines and optimize the care delivered in the combat and civilian trauma setting. We are seeking 391 patients with complete data to meet our a priori inclusion criteria. Our study will have major immediate short-term findings including risk prediction modeling to assess who is at risk for hypocalcemia, data assessing interventions associated with the incidence of hypocalcemia, and outcome data including mortality and its link to early hypocalcemia.

A Descriptive Analysis of Supermassive Transfusion Recipients Among US and Coalition Forces During Combat Operations in Afghanistan and Iraq.

INTRODUCTION: Hemorrhage is the leading cause of potentially preventable death on the battlefield. Resuscitation with blood products is essential to restore circulating volume, repay the oxygen debt, and prevent coagulopathy. Massive transfusion (MT) occurs frequently after major trauma; a subset of casualties requires a supermassive transfusion (SMT), and thus, mobilization of additional resources remains unclear. MATERIALS AND METHODS: This is a secondary analysis of a previously described dataset from the Department of Defense Trauma Registry. In this analysis, we isolated U.S. and Coalition casualties that received at least 1 unit of packed red blood cells (PRBCs) or whole blood (WB). Given a lack of consensus on the definition of SMT recipients, we included those patients receiving the top quartile of PRBC and WB administered within the first 24 hours following arrival to a military treatment facility. RESULTS: We identified 25,897 adult casualties from January 1, 2007 to March 17, 2020. Within this dataset, 2,608 (9.0%) met inclusion for this analysis. The median number of total products administered within the first 24 hours was 8 units of PRBC or WB. The upper quartile was 18 units (n = 666). Compared to all other blood product recipients, patients in the SMT cohort had a higher median injury severity score (27 vs 18, P < 0.001), were most frequently injured by explosives (84.9% vs 68.6%, P < 0.001), had a higher mean emergency department (ED) pulse (128 vs 111, P < 0.001), a lower mean systolic blood pressure (122 vs 132 mm Hg, P < 0.001), and a higher mean international normalized ratio (1.68 vs 1.38, P < 0.001). SMT patients experienced lower survival to hospital discharge (85.8% vs 93.3%, P < 0.001). CONCLUSIONS: Compared to all other PRBC and WB recipients, SMT patients experienced more injury by explosives, severe injury patterns, ED vital sign derangements, and mortality. These findings may help identify those casualties who may require earlier aggressive resuscitation. However, more data is needed to define this population early in their clinical course for early identification to facilitate rapid resource mobilization. Identifying casualties who are likely to die within 24 hours compared to those who are likely to survive, may assist in determining a threshold for a SMT.

Adherence to a Balanced Approach to Massive Transfusion in Combat Casualties.

BACKGROUND: Hemorrhage is the most common cause of potentially preventable death on the battlefield. Balanced resuscitation with plasma, platelets, and packed red blood cells (PRBCs) in a 1:1:1 ratio, if whole blood (WB) is not available, is associated with optimal outcomes among patients with hemorrhage. We describe the use of balanced resuscitation among combat casualties undergoing massive transfusion. MATERIALS AND METHODS: We conducted a secondary analysis of data from the Department of Defense Trauma Registry (DODTR) spanning encounters from January 1, 2007, to March 17, 2020. We included all casualties who received at least 10 units of either PRBCs or WB. We categorized casualties as recipients of plasma-balanced resuscitation if the ratio of plasma to PRBC units was 0.8 or greater; similarly, we defined platelet-balanced resuscitation as a ratio of platelets to PRBC units of 0.8 or greater. We portrayed these populations using descriptive statistics and compared characteristics between non-balanced and balanced resuscitation recipients for both plasma and platelets. RESULTS: We identified 28,950 encounters in the DODTR with documentation of prehospital activity. Massive transfusions occurred for 2,414 (8.3%) casualties, among whom 1,593 (66.0%) received a plasma-balanced resuscitation and 1,248 (51.7%) received a platelet-balanced resuscitation. During the study period, 962 (39.8%) of these patients received a fully balanced resuscitation with regard to both the plasma:PRBC and platelet:PRBC ratios. The remaining casualties did not undergo a balanced resuscitation. CONCLUSIONS: While a majority of massive transfusion recipients received a plasma-balanced and/or platelet-balanced resuscitation, fewer patients received a platelet-balanced resuscitation. These findings suggest that more emphasis in training and supply may be necessary to optimize blood product resuscitation ratios.

High-dose radiation exposure of cold-stored whole blood does not affect hemostatic function.

BACKGROUND: Whole blood (WB) transfusion is routinely used to resuscitate severely injured military trauma patients. Blood can be stored refrigerated while still maintaining reasonable function but is susceptible to environmental influences, including radiation exposure. Immune-compromised patients are transfused with irradiated blood to inactivate donor lymphocyte function (25 Gy per Association for the Advancement of Blood and Biotherapies [AARB] standard 5.7.3.2). However, there is limited information on function of WB exposed to high radiation doses. OBJECTIVE: This study aimed to determine if stored irradiated WB still retains function. This will be important if the stored blood supply is exposed to radiation in a combat situation or mass casualty incident when the need for blood will be high. METHODS: Whole blood collected from healthy donors was irradiated at 0, 25, or 75 Gy and stored at 4°C. Blood cell count, blood gas chemistry, thromboelastometry, platelet aggregation, and reactive oxygen species were measured before irradiation and at 1, 7, and 14 days of storage. Irradiated WB was compared with nonirradiated WB controls. RESULTS: Irradiated WB stored for up to 14 days was not significantly different than nonirradiated WB in most of the parameters measured. Stored blood showed expected changes associated with functional decline at longer storage times, but irradiation did not hasten the decline. There was a significant change in potassium and sodium ion concentrations after irradiation, but the functional relevance is not clear. CONCLUSION: High-dose irradiation had little effect on stored WB. Although there were changes in plasma sodium and potassium levels, there was little to no effect on hemostasis and blood cell viability. This suggests that stored blood subjected to a radiation event generating at least a dose of 75 Gy is still suitable for transfusion, which could be particularly important in the event of a mass casualty event where a large amount of blood is needed.

A natural history study of coagulopathy in a porcine 40% total body surface area burn model reveals the time-dependent significance of functional assays.

Various studies have reported discordant results on the magnitude and direction of burn-induced coagulopathy (BIC), which has recently been associated with multiple organ dysfunction syndrome (MODS) and death. The increased mechanistic understanding of BIC is due, in part, to novel assays that have expanded the armamentarium beyond traditional tests like PT and aPTT. Still, BIC is a dynamic process, and the progression is difficult to define in the thermally-injured. To this end, we aimed to enhance the understanding of burn-induced coagulation abnormalities by employing functional assessments of platelet aggregation, viscoelastic kinetics, and thrombin generation in an extensive burn model in swine. Anesthetized Yorkshire pigs sustained 40% total body surface area (TBSA) full-thickness contact burns and recovered in metabolic cages. Blood was collected at baseline (BL), as well as 6, 24, and 48 h after injury. A significant effect of burn (P < 0.0001) was seen on platelets, with mild thrombocytopenia apparent at 24 h. While slight decreases in aPTT were not significant, rotational thromboelastometry (ROTEM) analysis revealed hypercoagulation 6 and 24 h after burn by a decreased clotting time. Maximum clot firmness increased after burn, but was not statistically significant until 48 h. Hypercoagulation was not supported by platelet aggregation, as the response to ADP was greatly and persistently diminished, and the response to collagen was unchanged. Endogenous thrombin potential was significantly reduced at 6 and 24 h after burn (P < 0.0001), and also correlated with a number of ROTEM parameters and collagen-induced platelet aggregation. In contrast, PT was not correlated with other measured parameters. Taken together, novel coagulation parameters may be more sensitive than PT in characterizing coagulopathy in the setting of burns. The data presented herein makes initial strides to report the natural history of several of these variables over time in a large animal model of extensive burns, indicating early hypercoagulability followed by hypocoagulation. Future work will elucidate the effects of standard of care.